Contactless labyrinth seal obtained by additive manufacturing

Abstract

A contactless seal intended for being fitted in a wall and a shaft passing through an opening of the wall, the seal comprising a rotary member intended for being supported by the shaft and a stationary member intended for being supported by the opening, the stationary member being inserted around the rotary member while being rotatably movable relative to same, the rotary member having an outer surface provided with at least one circumferential rib and the stationary member having an inner surface provided with at least one groove, or vice-versa. Each rib is partially inserted into a corresponding groove in order to form a labyrinthine leak path. The rotary member and the stationary member are each made up of a single part, and the rotary member and/or the stationary member are obtained by additive manufacturing.

What is claimed is: 
     
       1. A contactless seal for a rotating shaft passing through an opening of a wall, the seal comprising a rotating member intended to be carried by the shaft and a fixed member intended to be carried by the opening of the wall, the rotating member being slotted into the fixed member while being mobile in rotation with respect to it, the rotating member having an outer face provided with at least one circumferential ridge and the fixed member having an inner face provided with at least one recess or vice versa, each ridge being partially engaged in a corresponding recess such that the inner face of the fixed member and the outer face of the rotating member jointly delimit a labyrinthine leak route, wherein the rotating member and the fixed member are each formed from one single part, wherein the rotating member and/or the fixed member is obtained by additive manufacturing,
 wherein the rotating member extends axially between first and second ends, wherein a deoiling element is provided at the first end and comprises a series of radial strips to centrifuge oil drops developing in a proximity thereof, wherein the radial strips extend outwards from the rotating member in a radial direction, and 
 wherein a ventilation element is provided at the second end of the rotating member and is configured to introduce fluid into one of the ends of the labyrinthine leak route to reduce a pressure difference between the ends of the labyrinthine leak route, wherein the ventilation element comprises fins carried by an end face of the rotating member, and wherein the fins extend outwards from the end face in an axial direction. 
 
     
     
       2. The contactless seal according to  claim 1 , wherein the fixed member comprises an edge situated in regard to the fins of the ventilation element to channel ventilated air towards the labyrinthine leak route. 
     
     
       3. An aircraft engine equipped with an accessory power transmission, comprising the contactless seal according to  claim 1 . 
     
     
       4. The contactless seal according to  claim 1 , wherein the radial strips extend further outwards in the radial direction than the at least one circumferential ridge. 
     
     
       5. The contactless seal according to  claim 1 , wherein the deoiling element is located adjacent an axial end of the fixing member.